Because the French are so precise, "loreal" would not satisfy them. It would have to be L'Oréal, with the accent. In the "dictionnaire de l'Académie française" which decides what IS French and what is NOT, there is no definition. Perhaps it is based on the word "l'or" which is gold. if "you are worth it" which WAS the original slogan the most precious thing is "gold." That is just my personal guess!